Real Madrid has been the most consistent club so far in both the domestic league and in international competition, indeed they don't always win every season but they have never experienced a dark period where their achievements have slumped as experienced by other clubs including their competitors in Laliga Barcelona which due to mismanagement experienced a financial downturn that resulted in them not being so impressive.
La Liga is a farmer league, the top 1,2, and 3 always Barcelona, Real Madrid and Atletico Madrid, they just swipe their position and there's no club can compete against them. I think the reason why Real Madrid is successful in international competition is their key players are still playing, it's not like Barcelona where most of their players were retired and they need to make a regeneration.
With Casemiro leaving and followed by Benzema, Real Madrid will make some regeneration. The big change happen when both Kroos and Modric performance aren't good enough, Real Madrid might have a bad season like Barcelona in the last year.
Real Madrid is always very careful selling players. They do not sell a player for whom they do not have a replacement in place. Real Madrid’s going with an old generation. I don’t remember when was the last time I saw this type of old player being in the main squad of Real Madrid.
I don’t know if La Liga is it farmers league or not. There are other leagues which are much less competitive compared to La Liga. But at the same time, I cannot say that La Liga is one of the most competitive as well. It is very true that three clubs are the most competitive, and those three, Barcelona, Real Madrid, and Atletico Madrid are generally in the top three.